Fluid pump



J. LIMING, JR

Jul 8, 1930.

FLUID PUMP 4 Sheets-Sheet Filed Feb. 19, 1925 [WWW l II- July 8, 3 .J. LLMING. JR

FLUTD PUMP- Filed Feb. 19 1925 4 Sheets-Sheet Juiy 8, 1930.

,1. LIMING. JR

Filed Feb. 19, 1.925 4 Sheets-Sheet 3 jwmZ/ af I J. LIMING. JR

Juiy 8, 1930.

FLUID PUMP Filed Feb. 19 1925 4 Sheets-Sheet Patented July 8, 1930 JOHN LIMING, J'R., OF PHILADELPHIA, PENNSYLVANIA FLUID PUMP Application filed February 19, 1925. Serial No. 10,272.

This invention relates to pumping apparatus, and more particularly to apparatus for pumping oil wells. 7

The principal object of the invention is to provide a pump of simple construction and operation which will be entirely practicable for pumping wells of great depth under conditions met in oil wells.

A more specific object of the invention is to provide novel, efiicient and thoroughly practical means for suspending the pipe lines in the well.

Another object of the invention is to simplify the pump mechanism and associated 1 elements, thereby creating a material saving not only in cost of manufacture, but also in the operation costs.

The invention further contemplates a novel and advantageous arrangement of parts for utilizing, at least in part, pressure created for one evacuating operation in a succeeding evacuating operation.

The invention further resides in certain novel and important details of construction including the gas or air-compressing mechanism as hereinafter'described and as illustrated in the attached drawings, in which:

Figure 1 is a semi-diagrammatic view showing partly in side elevation and partly in section a pump made in accordance with my invention;

Fig. 2 is a transverse section on the line 2-2, Fig. 1;

r Fig. 3 is a vertical section on the line 33,

Fig. 2;

Fig. 4 is a section on the line 4-4, Fig. 2;

Fig. 5 is a section on the line 5- 5, Fig. 4;

Fig. 6 is a transverse section on the line 6-6, Fig. 3;

Fig. 7 is a section on the line 7-7, F 1g. 6;

Fig. 8 is a vertical section of a well showing an installation of my apparatus;

Fig. 9 is an enlarged fragmentary section 5 illustrating a detail of the pipe suspension means;

- Fig. 10 is a section on 9; and

Fig. 11 is a diagrammatic view of the compressor mechanism and adjacent piping ilthe line 10-10, Fig.

lustrating a modification within the scope of the invention.

With reference to the drawings, a well to which my apparatus is applicable may be drilled in the usual manner and provided with the usual casing 1.

My apparatus in its preferred form comprises two pressure ducts 2 and 3 which extend through a discharge. duct 4 of sufficient size to hold the pressure ducts 2 and 3, and to afford also ample space for a liquid to flow therethrough. In operation the ducts, at least in part, take an upright position with their ends submerged in the liquid to be transferred, as illustrated in the drawings.

As clearly illustrated, both the duct 4 and each of the ducts 2 and 3 have their lower submerged end sections 5, 6 and 7 respectively, enlarged,'and the section 5 of the duct 4 carries at its lower end a valve casing 8 with which, as shown in Fig. 3, the pipes 2 and 3 also connect. The ducts 2 and 3 may be threaded or otherwise secured in the upper ends of passages 9 and 10, respectively, in the casing 8, both of which passages extend completely through the casing from top to bottom, and the lower end of each of these passages communicates, in the present instance through pipes 11 and 12, with independent valve casings 13 and 14 respectively,

the latter being suspended through the said pipes 11 and 12 from the casing 8. The casings 13 and 14 are identical and lie one beneath the other, and a passage 15 is rovided through the casing 13 for passage 0 the pipe 12 which communicates with the casing 1 1. Since the casin s 13 and 14:, exceptin an unimportant detail, are identical, it is necessary to describe but one, and it will be understood that the reference numerals apply equally to the elements of both of these parts. As shown in Fig. 1, the casings 13 and 14 may be secured together and braced by stud or other means.-

As shown in Figs. 3 and 7, the pipe 11 enters a cylindrical channel or chamber 16 extending inwardly from the to of the casing 13 and communicating wit 1 a similarly formed cylindrical chamber 17 extending in wardly from the bottom of the casing 13, the

chamber 17 being counterbored at its lower end, as indicated at 18, for reception of a valve seat 19, which latter is maintained in position by means of a sleeve 20 threaded into said counterbore. The valve seat 19 in conjunction with a ball element 21 forms a check valve which operates in obvious manner to control the passage to the pipe 11 through the chambers 16 and 17. Although it is preferred to form the valve chambers 16-17 as described by means of independent cylindrical bores entering the casing 13 from the top and bottom respectively and overlapping so as to form a communicating port and thereby a continuous passage through the casing 13, it is obvious that there may be considerable modification without departure from the essential characteristics of this part of the apparatus.

As previously stated, the valve casing 14 is in all respects similar to the casing 13, with the exception that it does not include the passage 15 for the pipe 12, this being obviously unnecessary.

The casing 8 in addition to the passage 9 and 10 comprises also chambers 22 and 23, said chambers being generally cylindrical in form and extending from the bottom of the counterbore 24 at the top of the casing, into which, in the present instance, the pipe 5 is threaded, completely through the casing to the bottom. Each of the chambers 22 and 23 is provided intermediate the top and bottom with an inner annular projection, 25 and 26 respectively, which form an abutment for a valve seating sleeve 27, which sleeve is supported in place against the under side of the projection by means of a follower sleeve 28 threaded into the lower end of each of the respective passages. Each of the sleeves 28 also is provided with an inward annular pro jection 29, similar to the projection 25, which forms an abutment on its under side for a valve seating sleeve 30.

Each of the chambers 22 and 23 is provided with a valve ball 31 and 32 respectively which seat upon the said sleeves 27, while valve balls 33 and 34 are provided, in the lower parts of the chambers 22 and 23 re spectivel which find a seat on the lower ends of t e sleeves-30, the balls 33 and 34 being normally held upon their respective seats by springs 35 which seat upon spring retainmg sleeves 36 threaded into the bottoms of the sleeves 28.

In order to revent displacement ofthe balls 31 and 32 mm the chambers 22 and 23,

a keeper late 37 is secured, by means of a screw 38 in the present instance, at the bottom of the said counterbore 24, this keeper plate, as well shown in Figs. 2 and 4, having apertured portions overlyin the tops of the chambers 22 and 23. Also, i prefer to form longitudinal recesses39 in the sides of the upper portions of the chambers 22 and 23 whereby ample space is provided for passage of oil through the chamber.

As shown in Figs. 4 and 5, the passages 9 and 10 communicate respectively with the chambers 23 and 22 through ports 40 and 41, said ports entering the passages 9 and 10 at a point intermediate the top and bottom and entering the chambers 22 and 23 at a point intermediate the valves 31 and 33 in the chamber 22, and 32'and 34 in the chamber 23. Through the ports 40 and 41 it will be apparent that the ducts 2 and 3 find communication through the chambers 22 and 23 with the lower end of the ducts 4, this communication being controlled by the valves 31 and 32 which permit a passage of fluid from the ducts 2 and 3 into the duct 4, while preventing a reverse movement of said fluid. Also, the valves 21 in the casings 13 and 14 permit passage of the fluid in which they are submerged into the ducts 2 and 3, while preventing a reverse flow from .the said pipes into the well.

Provision is made for discharging from the ducts 2 and 3 back into the surrounding body of liquid through the lower ends of the passages 22 and 23 which are controlled by the valves 33 and 34. The spring-pressed valves 33 and 34, however, normally close the lower ends of the passages -2 and 23, and the springs 35 are made to exert a predetermined pressure normally preventing the unseating of the valves 33 and 34, as hereinafter more fully described.

As regards the construction and arrangement of the valves controllin the lower ends of the ducts 2, 3 and 4, there o bviously may be considerable variation without departure from the invention.

Assuming, now, no pressure applied to either of the ducts 2 and 3, it will be apparent that with the lower ends of the ducts with the associated valve casings immersed in the oil or other liquid, the liquid will enter the ducts 2 and 3 through the check valves 21 at the bottoms of these ducts, and will rise in these ducts and also in the duct 4 throu h the ports 40, 41, and valves 31, 32, to t e normal level of the liquid body. It now pressure be applied to the ducts 2 and 3 from above, it will be apparent that the liquid in the ducts 6 and 7 will be forced through the ports 40 and 41 and through the valves 31 and 32 into the duct 4, the oil already occupying that duct being forced upwardly therein and eventually discharged through the discharge ducts 2 and '3, it will be apparent that liquid once again will pass through the valves 21, into the ducts 2 and 3.

Instead of operating the lines 2 and 3 simultaneously, it is preferred, for reasons hereinafter set forth, to apply pressure thereto and to relieve the; pressure alternately whereby one of the lines is being evacuated while the other is filling. This method not only provides a continuous flow of liquid from the discharge port 42, but also has other material advantages in operation, as hereinafter set forth. I v

The duct 4 is made sufliciently strong to sustain the extremely long lines of pipe required-for some oil well operations. The pipes employed for the ducts '2 and 3, however, are necessarily of comparatively small size and require some means of sup ort to prevent. buckling and rupture. uch means I have illustrated in Figs. 9 and 10. In this device, I provide a plate 43 of sufficient width to accommodate 0 enings for the pipes 2 and 3, and for we ges 44, entered from above between the edges of the openings and the pipes b means of which the pipes 2 and 3 may be secured in the openings. The plates 43 are not, however, of sufficient width to block the passage through the pipe 4, and the plates are further rounded at their ends so as to accommodate themselves to the shape of the pipe which they occupy.

As shown in Fig. 9, the plates are sufliciently long to extend completely across the interior of the pipe 4 and to overlie the in ner edge of the pipe.- The ends of the plate 43 may then be, secured between the ends of the adjacentsections of the pipe line 4, as well shown in the drawings, the usual coupling members 45being employed to secure the ends of the sections of the pipe 4 together. By this means the ducts 2 and 3 may be supported at suitable intervals within the "duct 4, and will be maintained in proper adjusted position within the said duct. The pipe lines may be assembled by simultaneously building up the lines 2, 3 and 4, applying the new top sections of the lines 2 and 3 prior to the corresponding sections of the line 4 so thatthe supporting devices 43' may be properly applied.

The duct 4 may be suspended in any suitable manner and I have illustrated in Fig. 1 one means for obtaining this suspension, which consists of a flange 46 threaded on the outside of the pipe 4 which -is of sulficient diameter to completely cover the top of the well casing 1. 'The latter may be provided at the top with a flange 47, and the flange 46 may be secured to this flange 47 by bolts 48 wherebynot only is the piping 4 suspended from the top of the casing, but the top of the casing is completely closed off, a desirable feature among other recognized by those familiar with oil Well operations.

It is also desirable, and I have provided means, to close off the top of the upper end of the duct 4,- a cap 49 being provided in the present instance which is bolted or otherwise secured at the top of the duct, provision being made in the cap 49 for passage of the piping 2 and 3.

The operation of the apparatus in so far described possesses many important advantages over apparatus of a like nature deve oped prior to my invention. A material advantage is obtained in the use of the outer duct 4 which constitutes not only a casing and a support for the pressure ducts 2 and 3, but also provides a simple and extremely practical means for suspending the entire piping in the well. The use of this construction also provides for complete well control as described above.

My pumping apparatus further comprises provides a closed system whereby the pressure utilized for evacuating the lines may be successively employed, thereby materially reducing the power required for operation.

As illustrated in Fig. 1, my compressor comprises two double cylinders 50-51 and 5253. In the cylinders 50 and 51, which are in axial alignment, a double piston 54 operates, this piston being actuated through the usual piston rod 55 from the crank shaft 56 of the compressor. Similarly the cylin- (lers 5253 are provided with a compound piston 57 operated from the crank shaft 56 through a piston rod 58. The cranks 59 and 60, to which the rods 55 and 58 are respectively connected, preferably are separated 180 so that as the iston 54 is moving downwardly, for examp e, on its intake stroke, the piston 57 is moving upwardly in its compression stroke.

In order to obtain the desired two stage effect. I connect the discharge port of the cylinder 52 with the intake port of the cylinder 51, the discharge port of the cylinder 50 being similarly connected with the intake port of the cylinder 53. The intake port of the cylinder 50 is connected as illustrated in Fig. 1 with the pipe line 3, while the pipe line 2 connects with the intake port of the cylinder 52. The discharge ports of the cylinders 51 and 53 are connected through a pipe line 61 with both the lines 2 and 3, and valves 62 and 63 are so arranged in the line 61 that the two compressor cylinders 51 and 53 may be connected simultaneously either with the pipe line 2 or the pipe line 3. The valves 62 and 63 are adapted to be operated together so that as one closes the other opens, and by means of these valves, operated simultaneously, the cylinders 51 and 53 of the compressor are, in the present instance, alternately connected with the pipe lines 2 and 3. The intake and discharge ports of each of the cylinders are provided with the usual check valves preventing a reverse flow through these ports, as indicated in the drawings.

Since automatic operation of the apparatus is desirable, I provide, in the present instance, a solenoid 64 including a plunger 65 having operative connection at opposite ends with the valve levers 66 and 67 of the valves 62 and 63 respectively. The 0 posite ends of the solenoid coil may both connected with one side 68 of an electric circuit including a generator 69, which latter may be actuated from the same source of power employed to operate the compressor, and which in the present instance is shown operated directly from the fly wheel of the compressor. The other side 69' of this circuit may extend to a tap at the center of the solenoid coil. as indicated at 70.

The electrical connection between the respectiveends of the coil and the conductor 68 are controlled in each instance by a pressure controlled switch, 71 and 72 respectively, and these switches are operatively connected to the ducts 2 and 3 respectively through suitable ducts 73 and 74. The arrangement is such that when pressure in the lines 2 and 3 has reached a certain predetermined amount, the switches are actuated to close their respective circuits, the circuits being automatically opened when the pressure drops below the aforesaid predetermined amount.

As hereinafter described, the switches 71 and 72 are closed alternately, and it will be noted that with the closing of one switch and the opening of the other, the direction of the current through .the solenoid is reversed, with a consequent intermittent reciprocation of the plunger 65, which on the respective strokes closes one of the valves 62-63 and opens the other. This portion of the ap aratus is completed by a safety valve 45, placed in the lines intermediate the valves 62-453 and the compressor cylinders, and the provision of valved auxiliary intakes 76-7 7 1n the pipe lines 2 and 3 providing for the automatic replenishment of the actuating fluid in the pipe lines when such is made necessary by leakage and other losses.

The ressure-actuated valves 62-63 may be in te form of the well known pressure gage, the pointers 78 constituting movable electrical contacts or' switch blades which at a given pressure meet fixed contacts 79 and thereby close the circuits.

Let it be assumed that in the position in up through the pipe 4 to discharge. When I the pressure in the duct 3 reaches .apredetermined point, the pointer 78 of the gage 72 has swung over to the point where it meets the contact point 79, thereby closing the solenoid circuit and causingamovement ofthe plunger 65 to the right, which closes the valve 62 and opens the valve 63. The pressure previousl built u in the duct 3 isnow relieved throug the cyiinders 54 and 53, the flow through these cylinders being free and uninfluenced by the pistons, the compressed fluid passing through the 0 en valve 63 into the duct 2 which now hol s liquid in its lower immersed section. The initial action therefore upon the opening of one valve and the closing of another is an automatic e ualization of pressures in the two ducts. l ollowing equalization, the pistons in the cylinders 50 and 53 start to compress the fluid in the system in the duct 2, at. the same time evacuatin the duct 3.

The pointer 78 of gage 72 a er having come into contact with the contact 79, as previously set forth, was immediately thereafter released by the ensuing pressure dro in the duct 3, and as the line 3 is evacuate by the action of the cylinders 54 and 53, this pointer 74 continues to move toward the zero posi tion, while the pointer 78 of the age 71 is moving toward the contact point 79 by reason of the increasing pressure in duct 2. When the duct 2 has been evacuated of its contained liquid, the pressure reaches the point where thepointer of gage 71 meets the contact 79, with the result that current flows into the solenoid in such direction that the plunger 65 is moved to the left to the position shown in the drawings, and the cycle is re eated.

t will be noted that as one set of cylinders is operating to build up pressure in theducts, the other set is idlin and this is permitted by the byass provi ed in each instance between inta e and exhaust. Thus, if the cylinders 52-51 are workin the intake and.

discharge ports of the cylinders 50-53 are by-passed through the pipe 61, connected and the end of the duct 3 which connects with the intake of the cylinder 50. A further adpressor, one cylinder vantageous feature is the coolin efiect on the'cylinders of the compressed uid which ,rushes therethrough during the aforedescribed equalizing operation, the fluid expanding as it flows and thereby having a considerable coolin effect. Arran ement of the two-sta e cylin ers as describe also aflords a desira le balance of pressures in the comeach set being under 1 compression at the same time.

Another characteristic of the pump is the Ycooling efiect ofthe outflowing oil or other liquid upon the'pi'es'siii'e pipes, which latter tend to heat up by reason of the successive high compressions of the actuating fluid. By

passing the pressure ducts through the discharge ducts, therefore, a desirable coolingeffeet 15 obtained in those parts of the duct extending into the well which cannot be cooled by air or other normal means. Also, the heat thus taken up by the oil will be of value where the oil contains water in obtaining the required separation of the elements, it being customary in such cases to heat' the oil in tanks so that the water may settle'to the bottom. i

There may be modifications without demodification I have illustrated in Fig. 11. In this instance, the valves 62 and 63 are relaced by a single three-way valve- 80,- this eing actuated electrically in themanner previously set forth. 7

I claim: 1. In a pump, the combination with an outer tubular casing closed at its lower end, a

plurality of pipes' inounted in the casing in substantially parallel relation therewit throughout and iormin inner passages, means for continuing sai passages through the closed lower end of the casing, said continuations being substantially in alignment and uniformin size with said inner passages, ports in said passages openin into the casing, a check valve adapted to c ose each of said ports from the casing side, and an independent check valve adapted to close the lower end-of each of said passages from the interior thereof at a point in each instance below the saidport through which the pas-' v: sage commumcates with the casin 2. In a ump, the combination with an outt er duct 21 apted to be suspended with its lower end submerged in a liquid and having a discharge opening at a point above the normal liquid'level, said duct being closed at the bottom, a plurality of pipes suspended with-.

in the outer'duetand forming inner passages, means for extending said passages througlifthe bottom of said duct, said extensions being substantiall in alignment and uniform in size with the inner passages, ports inner duct for formi the normal liquid level, a' valve casing at'the bottom of said duct havinga through passage, means including said passage and a pipe arranged within the outer duct for providing an inner passage extending through the outer duct and through the casing, a second and independent valve casing below said first casing and having connection with said inner passage a check valve in said second casing controlling a port to the outside thereof communicating with the inner passage, a chamber in said 'first casing communicatin with the outer duct, and a valve-controlle port connecting said chamber with the said assage.

4, n a pump, the combination with an outer duct adapted to be suspended with its lower end immersed'in a liquid to be trans-. ferred and having a discharge opening at a point above the normal liquid level, a valve casing at the lower end of said duct having a through passage, means including said passage and a duct arranged within said outer an inner passage extending through sai outer duct and the casing, a lower independent valve casing with which said passage communicates, ports in said upper Valve casing establishing communication between the inner passage and the outer duct, ports in the lower casing establishing communication between the inner passage and the body of ii uid in which the casings are immersed, an valves controlling said ports.

"5. In a ump, the combination with an outer ducthaving a valve casing at one end and a discharge port toward the other end, said valve casing comprising a channel extending completely therethrough and communicating at one end with the said outer duct and a second through channel, means including said second channel and an inner duct arranged withinthe outerduct for forming an inner passage which extends through said casing, the casing having a port establishing communication between this inner passage and the said channel, a check valve in the first named channel adapted to prevent a flow of liquid from the outer duct to said port, a second valveinsaid firstnamed channel normally preventin flow from said inner passage to the outside 0 the casing and adapted to open under a predetermined pressure within the channel, and a second and independent valve casing having a channel extending therethroughand communicating at one end with the inner pa, and a check valve preventing flow of liquid from the inner passage to the outside of said second casing.

6. In a pump, the combination with an outer duct having a valve casing at one end and a discharge opening toward the other end, said valve casing having chambers communicating with the outer duct and through passages, means including said through passages and pipes arranged within the outer duct for providing inner passages extending through the outer duct and through the casing, independent valve casings positioned below said first casing and respectively communicating with said inner passages, ports in said first casing connecting each of the chambers with one of the inner passages, a

port in each of said lower valve casings opening to the outside of the casing and communicating with the respective inner passages, and valves in said casings controlling the respective ports.

7. In a pump, the combination with an outer duct having a valve casing at one end a and a discharge port to'ward the other end,

said valve casing comprising a chamber communicating with the said outer duct and a through passage. a port opening into said chamber from the outside of said casing, means including said through passage and a pipe arranged within the outer duct for forming an inner passage extending through the casing, a port in said casing forming communication between said chamber and said inner passage, a valve in said chamber intermediate the last-named port and the outer duct and preventing flow of fluid from the said outer duct to the port, a valve normally closing the portfrom said chamber to the out side of said casing and adapted to open under a predetermined internal pressure, said valve adapted to be opened when the pressure in the chamber reaches a predetermined amount to thereby establish communication between the port connecting with the inner passage and the outside of the casing, a second and independent valve casing established below the first casing and having a chamber communicating with the inner passage and also with the outside of the casing, and a valve preventing flow of liquid from the inner passage to the outside of the casing while per-- mitting flow of afluid from the outside of the casing into said inner passage.

8. In a pump. the combination with an outer tube, of a valve casing at the lower end I thereof having through passages, means ineluding said through passages and a pair of pipes mounted in the interior of the tube for forming inner passages which continue through the valve casing, said valve casing having ports establishing communication between the outer tube and said passages, and check valves permitting a flow from the passages into the tube and preventing a reverse flow, a' pair of independent valve casings mounted one below the other and in alignment with the valve casin first named and connected respectively wit 1 said inner passages, said casings having ports constituting intakes for the said passages, and check valves preventing a reverse flow through the ports. a

9. In a pump, the combination with an outer tube, of a valve casing at the lower end thereof, said casing having passages extendin therethrough from top to bottom and va ved ports establishing communication between said passages and the outer tube, means including said through passages and a pair of pipes mounted in the interior of the tube for forming inner passages which continue through the said valve casing, means for continuing said inner passages beyond the bot tom of the valve casing, and valve means controlling intake ports in the extended ends of said passages in the interior of the tube and forming inner passages which continue through the said valve casing from to to bottom and communicate through va ved ports in the valve casing with said outer tube, said inner passages extending beyond the bottom of the valve casing, and valve means controlling intake ports in the extended ends of the passages.

10. In a pump. the combination with an outer tube having at the bottom a valve casing not appreciably greater in diameter than the tube, said casing having through passages, means including said passages and a pair of pipes mounted in the interior of the tube for forming inner passages which con tinue through the said casing, said pipes being of maximum effective diameter permit ting joint entrance into the, tube, check valves in said casing permitting flow from the inner passages into the tube and preventing a reverse flow, and check valves permitting flow into the lower open ends of said passages.

11. In a pump, the combination with an outer tube having at the bottom a ported valve casing not appreciably greater in diam eter than the tube, said casing having through passages, means including said passages and a pair of pipes mounted in the interior of the tube for forming inner passages which continue through the said casing and which communicate with the outer tube through the.

said casing port-s, check valves permitting a flow through the said ports from the inner passages, and a second set of check valves permitting flow into the lower open ends of sets of passages arranged in rectangular pattern and in communicating pairs with one passage of each pair in direct communication pipe connecting with the bottom casin ports with the tube and the other passage of each 1n the lower casings constituting inta es for pair communicating respectively with the said pipes, check valves in the casing controlling the passages communicating with the tube and preventing flow from the tube to the pipes, and valve means for controlling the other passages to permit influx thereto from the exterior of the casing but to prevent efiiux except through the connected passage.

13. In a pump, the combination with an outer tube, of a air of pipes mounted within the tube and orming inner ducts, a valve casing at the bottom of said tube having two sets of passages communicating-in pairs, with a passage of each pair communicating at the top directly with the tube and the other passages forming respectively oontinuations of the said inner ducts, said passages being arranged in rectangular pattern and symmetrically with respect to the vertical center line of the casing, check valves in said casing controlling the passages communicating with the tube and preventing flow from the tube to the inner ducts, and check valves controlling the lower open ends of said ducts to permit in- 1 flux thereto" from the exterior of the casing but to prevent-effiux except through the connected passage.

14. In a pump, the combination with an outer tube, of a pair of pipes mounted within the tube and forming inner ducts, a vave casing at the bottom of said tube having two sets of passages communicating in pairs, with a passage of each pair communicating at the top directly with the tube and the other passages forming respectively continuations of thesaid inner ducts, check valves in said casing controlling the passages communicating with the tube and preventing flow from the tube into the passages, pipes projecting below the valve casingand constituting extensions of the inner ducts, and an independent valve casing at the lower end of each of said projecting pipes with check valves permitting a flow 1nto the open ends of the ducts and preventing the reverse flow.

15. In a pump, the combination with an outer tube, of a pair of pipes mounted within the tube and forming inner ducts, a valve casing at the bottom of said tube having two sets of passages communicating in pairs, with a passage of each pair communicating at the top directly with the tube and the other passages forming respectively continuations of .the said inner ducts, check valves in said casing permitting a flow from the passages into the tube and preventing a reverse flow, pipes projecting from the lower end of the valve casing as continuations of the inner ducts, an independent valve casing at the lower end of each pipe arranged one above the other and in alignment with the casing first named, the intermediate casing having a passage for the the inner ducts, and check valves preventing a reverse flow through said ports.

JOHN LIMING, JR. 

